(1) Field of the Invention
This invention relates to a microprocessor and an image information processing system which include instructions for reproducing moving picture data for a movie and the like, more specifically to a microprocessor and the like suitable for preventing illegal copy of digital works.
(2) Description of the Prior Art
Improvements in multimedia techniques have made it possible for image information processing systems such as personal computers to directly reproduce Audio Visual (AV) data such as moving pictures stored in CD-ROMs. The AV data used here indicates multimedia data which is a mixture of image data, voice data, program data, etc. Also, "reproduction" indicates that the AV data is reproduced in a manner human being can see and hear.
FIG. 1 is a block diagram showing the construction of a conventional image information processing system for reproducing the AV data.
The conventional image information processing system is, for example, a system being mainly comprised of an IBM PC/AT compatible computer. This system includes speaker 60, CD-ROM 61, disk reproduction drive 62, MPEG decoder 63, hard disk apparatus 64, input unit 65, I/O bus 66, video signal processing unit 67, control unit 68, keyboard 69, mouse 70, and display apparatus 71.
CD-ROM 61 stores the AV data compressed under Moving Picture Expert Group 1 (MPEG1) (AV data compressed under MPEG is called MPEG data).
Control unit 68 is comprised of a general-purpose microprocessor 681 connected to processor bus 682, bus I/F 683, and main memory 684 in which a reproduction control program is loaded.
MPEG decoder 63 is comprised of a multiplier and the like and is a card-type module that generates image data and voice data by decompressing the MPEG data, that is by performing an inverse encoding, an inverse quantization, an inverse Discrete Cosine Transform (DCT). MPEG decoder 63 is included in an expansion card box which is not shown in the drawings.
Video signal processing unit 67 converts the image data and voice data input through I/O bus 66 into an image signal and a voice signal respectively, then outputs the signals to display apparatus 71 and speaker 60. Note that "data" indicates digital information, "signal" indicates analog information.
Control unit 68 of the above constructed conventional image information processing system, on receiving a reproduction instruction from a user through keyboard 69 or mouse 70, allows input unit 65 to detect the instruction and reads MPEG data from CD-ROM 61 to main memory 684 by controlling disk reproduction drive 62.
Control unit 68 then sends the MPEG data to MPEG decoder 63 for decompression. Control unit 68 transfers the decompressed image data and voice data to video signal processing unit 67 to convert them to an analog image signal and an analog voice signal. The analog image signal and the analog voice signal are then output to display apparatus 71 and speaker 60.
The conventional image information processing system achieves the reproduction of the AV data stored in CD-ROM 61 through interactive operations with the user.
However, the conventional image information processing system has the following problems.
Firstly, the system requires an independent card module, or MPEG decoder 63. That is, to enjoy the reproduction of the AV data, the user needs to purchase an independent card module, namely, MPEG decoder 63 as well as a general-purpose personal computer and install it to the expansion card box. Also, one slot of the expansion card box is occupied by the card module.
Secondly, the conventional system has no means to prevent illegal copies of the AV data (digital work) stored in CD-ROM 61. With the above system, it is easy to copy the AV data from CD-ROM 61 to hard disk apparatus 64 or a write-enabled optical disk and the like and sell without a permission by the copyright owner. If the medium prices are raised to include the loss generated by the copyright infringement, users will have great disadvantages.